The Pallas's leaf warbler or Pallas's warbler (Phylloscopus proregulus) is a leaf warbler which breeds in southern Siberia (from Novosibirsk Oblast east to Magadan Oblast), northern Mongolia, and northeastern China. It is strongly migratory and winters mainly in subtropical southern China and northeastern Indochina, but also in small numbers in western Europe (Wiki).
This migrant was in Wells Woods, Norfolk and arrived after some easterly winds blowing in from its home in Siberia.
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